Buggy code:
@ SuppressWarnings ( "nls" ) public final class ActFmSyncService { @ Autowired TagDataService tagDataService ; @ Autowired MetadataService metadataService ; @ Autowired TaskService taskService ; @ Autowired ActFmPreferenceService actFmPreferenceService ; @ Autowired ActFmInvoker actFmInvoker ; @ Autowired ActFmDataService actFmDataService ; @ Autowired TaskDao taskDao ; @ Autowired TagDataDao tagDataDao ; @ Autowired UpdateDao updateDao ; @ Autowired MetadataDao metadataDao ; public static final long TIME_BETWEEN_TRIES = 5 * ( DateUtilities . ONE_MINUTE ) ; private static final int PUSH_TYPE_TASK = 0 ; private static final int PUSH_TYPE_TAG = 1 ; private static final int PUSH_TYPE_UPDATE = 2 ; private String token ; public ActFmSyncService ( ) { } private class FailedPush { int pushType ; long itemId ; public FailedPush ( int pushType , long itemId ) { } } private final List < ActFmSyncService . FailedPush > failedPushes = Collections . synchronizedList ( new LinkedList < ActFmSyncService . FailedPush > ( ) ) ; Thread pushRetryThread = null ; Runnable pushRetryRunnable ; public void initialize ( ) { } private void initializeRetryRunnable ( ) { } private void addFailedPush ( ActFmSyncService . FailedPush fp ) { } public void pushUpdateOnSave ( Update update , ContentValues values , Bitmap imageData ) { } private boolean notPermanentError ( Exception e ) { } public void pushTaskOnSave ( Task task , ContentValues values ) { } public void pushTask ( long taskId ) { } public void pushTag ( long tagId ) { } public void pushUpdate ( long updateId ) { } public void pushUpdate ( long updateId , Bitmap imageData ) { } public void pushTagDataOnSave ( TagData tagData , ContentValues values ) { } private void toastSuccessOrFailure ( String error ) { } public void fetchTagDataDashboard ( boolean manual , final Runnable done ) { } public void fetchTag ( final TagData tagData ) throws IOException , JSONException { } public void fetchTask ( Task task ) throws IOException , JSONException { } public int fetchTags ( int serverTime ) throws IOException , JSONException { } public void fetchActiveTasks ( final boolean manual , Runnable done ) { } public void fetchTasksForTag ( final TagData tagData , final boolean manual , Runnable done ) { } public void fetchUpdatesForTag ( final TagData tagData , final boolean manual , Runnable done ) { } public void fetchUpdatesForTask ( final Task task , boolean manual , Runnable done ) { } public String setTagPicture ( long tagId , Bitmap bitmap ) throws ActFmServiceException , IOException { } private MultipartEntity buildPictureData ( Bitmap bitmap ) { } public JSONObject invoke ( String method , Object ... getParameters ) throws ActFmServiceException , IOException { } private abstract class ListItemProcessor < TYPE extends AbstractModel > { protected Long [ ] remoteIds = null ; protected abstract HashMap < Long , Long > getLocalModels ( ) { } protected abstract void mergeAndSave ( JSONArray list , HashMap < Long , Long > locals ) throws JSONException { } public void process ( JSONArray list ) throws JSONException { } protected void readRemoteIds ( JSONArray list ) throws JSONException { } protected void readIds ( HashMap < Long , Long > locals , JSONObject json , RemoteModel model ) throws JSONException { } protected HashMap < Long , Long > cursorToMap ( TodorooCursor < TYPE > cursor , DatabaseDao < ? > dao , LongProperty remoteIdProperty , LongProperty localIdProperty ) { } } private void invokeFetchList ( final String model , final boolean manual , final ActFmSyncService . ListItemProcessor < ? > processor , final Runnable done , final String lastSyncKey , Object ... params ) { } protected void handleException ( String message , Exception exception ) { } private boolean checkForToken ( ) { } public static class JsonHelper { protected static long readDate ( JSONObject item , String key ) { } public static void updateFromJson ( JSONObject json , Update model ) throws JSONException { } public static void readUser ( JSONObject user , AbstractModel model , LongProperty idProperty , StringProperty userProperty ) throws JSONException { long id = user . optLong ( "id" , ( - 2 ) ) ; if ( id == ( - 2 ) ) { model . setValue ( idProperty , ( - 1L ) ) ; if ( userProperty != null ) { JSONObject unassigned = new JSONObject ( ) ; unassigned . put ( "id" , ( - 1L ) ) ; model . setValue ( userProperty , unassigned . toString ( ) ) ; } } else if ( id == ( ActFmPreferenceService . userId ( ) ) ) { model . setValue ( idProperty , 0L ) ; if ( userProperty != null ) <START_BUG> model . setValue ( userProperty , "" ) ; <END_BUG> } else { model . setValue ( idProperty , id ) ; if ( userProperty != null ) model . setValue ( userProperty , user . toString ( ) ) ; } } public static void tagFromJson ( JSONObject json , TagData model ) throws JSONException { } public static void taskFromJson ( JSONObject json , Task model , ArrayList < Metadata > metadata ) throws JSONException { } private static String filterRepeat ( String repeat ) { } } }

Fix:
model . setValue ( userProperty , ActFmPreferenceService . thisUser ( ) . toString ( ) ) ;